Settings

The settings panel is raised from the top toolbar of the application:

One raised, it shows a number of different tabs, each being focused on a part of the available settings:

Anti-aliasing: is for anti-aliasing settings,
Plants: manages densities, viewing distances and other settings relative to plants.
Shadows: contains all parameters for the setup shadows cast by the sun.
Atmo.: Lists atmospheric settings. Those are settings, not to be confused with the definition parameters of Atlases.
Performance: Lists specific performance settings that apply to the whole system.
Misc.: Other stuff that could not fit into another tab...

Two settings presets can be selected from the top combo box. They allow to define two sets of parameters. The Default preset holds parameters for realtime interaction in the viewport while the Render preset can be selected when doing any rendering operation (see Rendering). The properties under the Render preset are high quality settings not necessarily suited for realtime.

Note:

Editing the Default preset is immediately visible in the main viewport.

Anti-aliasing

NDunes features two different anti-aliasing techniques, each dedicated to a specific rendering need:

The Full Scene Anti-Aliasing, known as FSAA, renders the image at a greater size than displayed and then reduces it back to the wished size. A value of x2 renders an image whose total size is twice the width and height of the requested image size for instance. Anti-aliasing produced by FSAA is top quality due to the brute force supersampling of the image.
The Temporal Anti-Aliasing, known as TAA renders the image with slightly different pixels positions each frame and accumulates the result to generate an anti-aliased image.

TAA is meant to be used mainly for real-time display, but it can also be used for film rendering when the "TAA number of averaged frames" counter is greater than 1. For instance when set to 16, there will be 16 frames rendered and accumulated to produce a final image. TAA is fast, but TAA with frames accumulation is slow due to the repeated rendering of a frame. Note that TAA with accumulation only works when rendering. It does not work in the viewport display. FSAA is meant to be used for film rendering and its slower than normal TAA. FSAA is stable in animation, while TAA can exhibit motion artifacts. FSAA overrides any TAA setting when enabled, so only FSAA is enabled at a time.

FSAA is activated by setting a size multiplier above x1. TAA is enabled or disabled just by the check box aside.

If you're not familiar with temporal anti-aliasing, don't bother modifying any of these settings. If you wish to get into the details of it:

TAA movement threshold: Is a threshold used to smooth more or less the image accumulation when there are objects in motion (either due to their animation or due to camera movements). A low value of this setting will tend to smooth more the results while a high value will tend to get sharper images with possibly more flickering. Differences resulting of this value's setup are not easy to catch and are visible only in motion.
TAA minimal accumulation alpha: The minimal percentage of influence of the incoming frame in the color history.
TAA maximal accumulation alpha: The maximal percentage of influence of the incoming frame in the color history. The algorithm will automatically select which alpha is suited best for representing the final image depending on the various conditions in the image (motion, colors...).
TAA number of averaged frames: This setting has no effect in display mode. It only works for film or still image rendering.

Plants settings

Plant type: Dropdown list with our four categories of plants. Select the type of plants you wish to modify there.
Plants density: This is a global plants density term applied to all plants of that type in the current scene. The default value is 8 for a range in [ 0.0, 16.0 ]. This density term comes last in the evaluation of the density of plants, right before displaying them.
Plant fade start (m): This is the distance at which plants prisms start to fade. As detailed in the Overview of the plant display system and in the Plants splats when far away, this modifies the prisms area for all plants of the chosen type.
Plant fade stop (m): This is the distance at which plants prisms have disappeared.
Splat overlap: This is the overlap distance between prisms and splats. See here: Plants splats when far away for details.
Force real plant shadow: For a high quality rendering it may be wishful to override the shadowing method defined at the plant level (see the real mesh shadow setup in Plants). By checking this box, all plants of the selected category will have their 'real mesh shadow' setting overriden and forced on. This'll probably slow down the display, but all plants will be then shadowed using exact meshes, resulting in a greater quality.
Plants exact spawn: This setting changes the accuracy of the plant seeding when turned on. The seeding of plants will follow more carefully the density maps, revealing thinner details that could have been missed by the default plant scattering method. Enabling this option will reduce the terrain update speed a bit. This is illustrated below:

Exact spawn enabled in the right image

Plants spawn offset: This setting rules the distance at which plants are seeded and generated by the system. On increasing the setting value, plants get seeded from closer distances. The consequence of this is that the plants effects on the ground (AO field, plant splats) are less visible in the distance. So increasing this setting will tend to reduce the quality of the long range visibility of plants. On the other hand, the benefit is that terrain updates will be much faster. Similarly, reducing the value does the opposite: plants are seeded from farther so real position of plants are identifiable from much farther. And of course, this slows down terrain updates. For fast movements, a +1 value should be considered. For high quality images, 0 or -1 might be privileged.
Plants mesh fade offset: This slider value modifies Plants mesh fade start and stop distances, by adding the slider value (in meters) to the fade distances of each plant. This applies to all plants in the selected category of plants. This is a convenient way to increase the quality of the display by pushing the fade distances away with a positive distance or to increase performances when there are too many meshes on screen by reducing the fade distances.

Sun Shadow Map settings

This setting tab defines parameters for the sun shadow maps and only for it. Sun shadows are cast up to a very long distance.

Blurring: This is the blurring term applied to shadows produced by the sun. To get sharper shadows, this value can be reduced.
Biasing - angular: This is a biasing control for the shadows. Increasing this value will reduce possible fake "contact" shadows which is a problem inherent to the shadow map casting method.
Biasing - constant: This is a biasing control for the CSM. As for the angular bias, this parameter will help reducing possible fake contact shadows that can arise with shadow mapping techniques.
Focused shadow area scale: The sun shadowing technique increase shadow quality near the focus point of shadows. The focus point is generally set during mouse manipulations of the main camera (this is the blue sphere where the mouse is clicked). The concentration of shadows may be increased or decreased using this slider control.
Alpha threshold for prisms: This parameter defines the opacity level through which shadows are captured for prisms. Modifying this value will change how the light gets through prisms of plants. Note that for plants meshes, the alpha threshold of shadowing is ruled by the material alpha threshold parameter. For prisms however, we have one global value for all plants prisms in the scene.
Size: This is the size of the shadow map in pixels. Increasing this size will reduce performances but also significantly improve shadow quality.
Star GI strength in shadows: This is another type of setting, that influences the lighting and shading model when in shadows. This can be used to strengthen or reduce the effect of the approximated global illumination (GI) calculated in real-time, when in shadows. So increasing this value can remove the darkness of deeply shadowed zones.
Translucency strength in shadows: This is a term that rule how black shadows are when going through leaves of a plant. Increasing this value will make plant leaves brighter when seen through.

Atmospheric settings

Atmospheric landscape shadows: A must have. Not free in terms of real-time rendering performance. Turning this on will use the Cascaded Shadow Maps (CSM) detailed above to enhance atmospheric scattering calculations, revealing the sun shafts cast by the landscape. For these atmospheric sun shafts to be visible, we may need a quite turbid atmosphere, as detailed here (Defining a planet's atmosphere.). Effects of this setting are illustrated below:

No atmospheric landscape shadows to the left; shadows enabled to the right

Atmospheric clouds shadows: Similarly, atmospheric clouds shadows plays an important role in the rendering of clouds by turning on clouds shadows casting effects over the atmosphere, creating god rays when seen through tiny holes.

No atmospheric clouds shadows to the left; shadows enabled to the right

Atmospheric landscape / plants / clouds samples: This is a number of samples used in the calculation of atmospheric effects. Each sample category influences the level of noise when looking at the corresponding category element in the scene. The noise level when looking at the plain sky is ruled by the landscape samples count. Increasing the number of samples has a rendering cost that'll be used to reduce the level of noise in the resulting image.

Note that atmospheric effects in NDunes are plain volumetric effects so while they have a significant cost they are working regardless of the position of the sun in the scene, unlike typical post-processing effects that are based on a visible sun.

Atmospheric gamma: It's also possible to apply a gamma transform to the lighting produced by the atmosphere. This transform can be used noticeably to lighten the atmosphere in the distance and to fade it to a greyish-whitish tint.

Clouds fade start: This is the starting distance of the clouds fading. Clouds will fade to Clouds covers.
Clouds fade start: This is the ending distance of the clouds fading.
Clouds relighting:: This setting rules the strength of the relighting performed by clouds layers when the sun is occluded. Practically, when shadows are occluding the sun, part of the lighting is re-emitted by the clouds layers as an hemispheric lighting term. This provides a dull tint sourced from clouds layer that enhances the skylight contribution. This is illustrated below:

No clouds relighting on the left, 50% (default) clouds relighting on the right

Clouds density: As for plants we have a final density control that can be used to adjust the visible density of clouds.
Clouds resolution downscale: As clouds can be extremely costly to render, this option can be used to have them rendered at an under sampled resolution and upscaled after rendering back to the plain screen size. While this'll cause a reduction of the visual quality, the performance savings can be worth it during setup phases that are intensively using clouds.

Miscellaneous settings

Planet on-screen patches split size: The two settings here (on-screen and off-screen patches screen sizes) are related to the visual quality of Terrains. These are pixel settings that define the dynamic mesh subdivision level of the terrain for the display. The subdivision level of the terrain mesh depends on the resolution of the window rendering it. This means that for a given setting value, the number of triangles used to render the terrain will vary. So this is a kind of "absolute" qualitative value, which is based on pixels rather than on the field of view. On a wide screen, the rendering of terrains can consume hundreds of millions of triangles so that the quality level remain good per pixel. The on-screen patches split size modifies the terrain which is directly visible (e.g. on the screen display).
Planet off-screen patches split size: This other setting value defines the subdivision level of the terrain, but this time for all the terrain that is around the camera and not directly visible. This value is greater than the on-screen one as we don't see the terrain directly. When rotating the camera or moving it, terrain parts that become visible and that were split until that off-screen size will be now split using the on-screen size. Terrain parts that get out of the direct view get unsplit down to the off-screen size. So keeping a large gap between the two values will tend to make terrain refinement more visible when turning the head around. At the other extreme, if values are identical for both settings, no terrain update should occur when turning the head around. But in this case, the time taken to prepare the terrain subdivision outside of the view might have taken some time and some resources. So generally, a moderate gap between the two values is preferred. Feel free to play with this and to turn wireframe mode on to see how this works.

Number of prisms passes: This parameter has a big effect on performances. It rules the number of rendering passes we'll use to blend prisms together making nice soft effects with plants that fade away in the distance. At the minimal value (=1) there's only one pass used to render prisms. The result is then pure alpha masking of plants with a low quality and a faster display. At the intermediate level (=2) we do see the blending and for the most of it the quality is acceptable. Performance savings are still significative. At the default level (=3), the quality is better and of course this has a significant impact on the framerate. This setting also rules the number of transparency layers used to render transparent materials in geometries.

GI samples spread: This one affects the spreading of GI samples computed for Geometries. See Adding global illumination for details.

Performances

Landscape update operations time per frame: This setting rules the time taken by the system - each frame - to do landscape update operations. A high number in this setting will provoke slowdowns in the frame rate when there are lots of terrains updates that have to be handled. On the other side, a small number will preserve a constant framerate and do a minimal number of landscape operations each frame.

Performances

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